1. Results and Discussion
Quantitation of Maltodextrin in Botanical Extract Raw Ingredients Using Proton NMR Isaac Leea, Yanjun Zhangb, Kan Heb, Piyush Purohita, Prashant Ingleb, Quanyin Gaoa*, Peter Changb, and Gary Swansonb   aHerbalife Manufacturing, LLC, Crescent Bay Drive, Lake Forest, CA 92630, USA bHerbalife International of America, 950 West 190th Street, Torrance, CA 90502, USA
Abstract
Calculation Method 1
An NMR test method was developed to quantitate Maltodextrin in various botanical extracts. This method was applied to characterize the botanical extract raw materials and evaluate the Maltodextrin content.
Introduction
Fig. 1 Typical NMR Spectrum of Maltodextrin
Maltodextrin is widely used in dietary supplement and food industry as an excipient. Excipients are used to help with standardization, to improve flow of the powder, to balance pH, to stabilize active compounds etc. There are several types of excipients used in herbal extract process. Maltodextrin is one of the mostly used excipients. It is necessary to analyze the content of maltodextrin to fully characterize or standardize a botanical extract used in dietary supplement. In this study, we employed proton NMR spectrometry to quantitatively analyze the content of maltodextrin in various botanical extracts.
Calculation Method 2
Experimental
Fig. 2. Overlap of NMR spectra of green tea extract, maltodextrin and their mixture
Reagents
Nicotinamide 99.5% or equivalent (reference standard)
M150 Maltodextrin
DSS (4,4-dimethyl-4-silapentane-1-sulfonic acid)
Deuterium Oxide 99.9%
Equipment and Materials
400 MHz NMR spectrometer (Topspin 3.1) Bruker AVANCE III
NMR Conditions
Relaxation delay (d1) s
Number of scans (NS)
Sweep width (SW) ppm
Pulse width (PW30) µsec
Results and Discussion
Five different concentration of M150 maltodextrin standard in deuterated water (3.1 mg/mL , 6.25 mg/mL , 12.5 mg/mL , 25 mg/mL, and 50 mg/mL) were analyzed, and a calibration curve was generated using integrated proton signal of a maltodextrin peak (δ 5.30 – 5.5 that corresponds to (1→4)-α-linkage in polysaccharide chains) against the standard concentration. The content of maltodextrin in the botanical extracts was calculated from the calibration curve. A coefficient of determination (R2) for the calibration curve of >0.99 was obtained.
Fig. 3. Overlap of NMR spectra of guarana seed extract, maltodextrin and the their mixture
Conclusion
An NMR quantitative method was developed for analyzing maltodextrin content in botanical extract where maltodextrin is commonly used. This test method was found to be practical for analyzing botanical extract samples and for characterizing the content of maltodextrin. Maltodextrin content of about 10% to 70% of various materials were found from different botanical extract samples.
Fig. 4. Overlap of NMR spectra of licorice extract, maltodextrin and their mixture